Just happened this morning. When I try filling the pump shuts off in about 10 seconds like the tank is full. I tried pulling the pump nozzle out about half way and it didnt change anything, still shut off in about 10 seconds. The check engine light has not come on. Truck runs fine. Since i've had the truck my purge valve has made a hissing noise that would come and go every day. When it does making the hissing noise, if I pop off the gas cap it will go away but eventually come back after the cap is put back on. Would these two problems be caused by the same thing? I have heard the hissing noise is normal. I hope it is just a clogged vent tube that I can clear out easily. Thanks in advance for any info.

Everything seems to be just fine and nothing is broke and no leaking. Been researching this issue tonight and have come up with quite a few possibilities on this but just need to find the actual reason causing this to happen.

Someone played a trick on a friend of mine by stuffing a rag into the filler tube where you couldn't see it.
Really ticked him off whenever he got gas.Took him forever to fill up until he found out and fished it out of there.

Problem solved!! Well at least so far. I took the vent hose off the filler neck and put a small hose inside of of it and blew through it and it cleared. Did the same on the metal hose that is part of the filler neck. Drove with the gas cap off until the gas cap light went on (read this on another forum to do) then put cap back on, light went off after a while, drove another 10 miles back to the same gas station I originally had the problem with from the beginning, filled up at the same pump and now all is well!! Thought it was going to end up having to replace the vapor canister but so far so good. Hopefully no more issues but if so the next step would be the canister.